The present invention relates generally to a coupling device for connecting a towed vehicle, such as a trailer, with a towing vehicle, such as a truck. More particularly, the present invention relates to a coupling device that includes at least one cushion for dampening shocks from the lateral direction, and preferably includes a second cushioning assembly for dampening shocks from the axial direction.
Various types of coupling devices for connecting a towing vehicle with a towed vehicle are currently available. One popular way of connecting the towed vehicle to the towing vehicle utilizes two separate components--a ball and a socket--where the ball is affixed to the towing vehicle and the socket, within which the ball is to be seated, is affixed to the towed vehicle.
One specific type of ball and socket coupling device available for coupling heavyweight trailers to trucks is commonly referred to as a "gooseneck" coupler. The socket portion of the gooseneck coupler generally includes a long, vertically extending shaft (the "gooseneck") of several feet in length. This shaft is rigidly attached to the trailer so that it extends vertically downwardly from the trailer. The ball portion of the coupler is normally rigidly affixed to the rear portion of the truck, either directly over the rear axle or somewhat in front of the rear axle. With the ball portion positioned in this manner, a better weight distribution of the trailer is achieved because the weight of the trailer is not creating a downward force on the unsupported rearmost portion of the truck.
Gooseneck couplers are commonly used with larger trailers that include an overhang portion at the front end thereof. This overhang portion enables the truck/trailer combination to make relatively sharp turns without having the front of the trailer contact the back of the truck because the frontmost portion of the trailer is actually positioned over the top of the rearmost portion of the truck. In this manner, the trailer is free to pivot with respect to the truck through a relatively wide angle, without the loss of a significant amount of storage space in the trailer.
While gooseneck couplings are commonly used with the overhang trailers just described, they may also be used with trailers without an overhang portion, which instead include an A-frame extending horizontally from the front end of the trailer. The "A" shape of the A-frame may be seen when the trailer is viewed from above. Similar to the overhang, the A-frame also permits a relatively wide turning radius without the front of the trailer contacting the rear of the truck because the A-frame serves to provide sufficient distance between the front of the trailer and the back of the truck. Combinations of the A-frame setup and an overhang trailer are also available.
One problem with some of the currently available gooseneck coupling devices is caused by a lack of shock absorption, or at least insufficient shock absorption. During normal operation, shocks may be transferred between the trailer and the towing vehicle. These shocks may arise from a variety of sources such as uneven road surfaces, potholes, high winds acting upon the trailer, forces created by altering the velocity of the vehicle (i.e., starting or stopping the vehicle's motion), or the torsional forces that are created when the vehicle/trailer combination makes a turn. Further, as these shocks are created from a variety of sources, they also act in a variety of different directions. For example, the bulk of the force of a torsional shock occurs from the lateral direction, while the bulk of the force from a pothole occurs in the vertical direction, or along the axis of the vertically extending shaft.
No matter which direction the force of the shock is directed, similar consequences may result. Undampened shocks transferred within the coupling device can serve to weaken the materials of the coupling device, which may result in failure of the coupling device over time. More severe shocks can also instantaneously break the coupling device, if these severe shocks are not properly dampened. Besides requiring replacement, a broken coupling device can also lead to a dangerous traffic accident if the break occurs while traveling at high speeds, which is most often the condition under which a break is likely to occur.
An additional problem with the currently available coupling devices relates to the security of the coupling. After the trailer and the towing vehicle are connected to one another, they should be locked together. If no lock is available for the coupling, vandals or thieves may simply uncouple the trailer from the towing vehicle when the towing vehicle and trailer are parked. At minimum, this unauthorized uncoupling results in wasted time because the trailer and towing vehicle will have to be re-coupled. At worst, a valuable trailer and expensive cargo may be lost if the entire trailer, including the cargo therein, is stolen by being removed from the towed vehicle during an extended period of being parked.
Accordingly, in response to the problems discussed above, a primary object of the present invention is to provide an improved coupling device for coupling a towing vehicle with a towed vehicle, where the present coupling device includes adequate shock dampening.
Another object of the present invention is to supply an improved coupling device that includes shock dampening for laterally directed shocks.
A further object of the present invention is to provide an improved coupling device that includes sufficient shock dampening for axially directed shocks.
An additional object of the present invention is to provide an improved gooseneck coupling device with adequate shock dampening to avoid premature failure of the coupling.
Yet another object of the present invention is to supply an improved coupling that includes an effective, low-cost way of locking a trailer with a towing vehicle in a coupled state.